Inverse Square Law 5 : The relationship that states that electromagnetic radiation intensity is inversely proportional to the square of the distance from a point source. (Basics of Radiation: Definitions, REAC/TS)
U.S. Department of Health and Human Services, Office of the Assisstant Secretary for Preparedness and Response, National Library of Medison, Radiation Emergency Medical Management (REMM), Dictionary of Radiation Terms, Washington, DC, USA 2014. http://www.remm.nlm.gov/dictionary.htm, (Dzstr/ Rad Emr - Amer) {822}